US2521788A

US2521788A - Electronic counter

Info

Publication number: US2521788A
Application number: US580446A
Authority: US
Inventors: Igor E Grosdoff
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1945-03-01
Filing date: 1945-03-01
Publication date: 1950-09-12
Anticipated expiration: 1967-09-12

Description

Sept. 12, 1950 E. GROSiDOFF 2,521,788

' ELECTRONIC COUNTER Filed larch 1, 1945 3 Sheets-Sheet 1 mmvron. 13m 15 600500;;

HT'TORNFY Sept. 12, 1950 E. GROSDOFF ELECTRONIC coun'ma Filed March 1, 1945' SSheets-Sheet 2 BYCEA Patented Sept. 12, 1950 ELECTRONIC COUNTER Igor E.'Grosdoff, Princeton, N. 1.,

assignor to Radio Corporation oi America, a corporation of Delaware Application March 1, 1945, Serial No. 580,446

Claims.

' This invention relates to electronic counters having a cycle oi operation which is completed in response to the application of a predetermined number of electrical impulses, and has for its principal object the provision of an improved counter and method of operation whereby the construction and operation of such counters are simplified and improved.

The counter of th present invention is similar to that of a copending application or Flory, Serial No. 467,032, filed November 26, 1942, now Patent No. 2,410,156, in that it includes a plurality of multivibrator units which are connected in cascade and have the last multivibrator unit interconnected with an intermediate multivibrator unit for causing the counter to complete its cycle of operation in response to a number of electrical pulses other than that required to complete such cycle of operation when all the units are connected in a loop.

While the counter of the aforesaid Flory application is satisfactory for continuous operation, the fact that it must be completely filled once before it begins to count correctly involves some difliculty in cases where the counter is frequently started and stopped and the counter is required to afford a correct indication under these conditions. In accordance with the present invention, this difliculty is avoided by so interconnecting the various multivibrator units that no preliminary filling oi the counter is required to make it complete its cycle of operation in response to the desired number of electrical impulses.

The illustrated form of the invention includes four multivibrator units so interconnected as to complete their cycle of operation in responses to the application of ten electrical impulses and to properly indicate or register the accumulated count at any point in the cycle. These connections are such that the various units are turned over in the usual manner in response to the number of impulses required to turn over all the units once. When the last unit is turned over, however, there is applied to the grids of the second and third units a negative potential which causes these units to be skipped during the rest of the operating cycle of the counter. This negative potential is applied from one anode of the last unit through a coupling capacitor and a duodiode- Output pulses at one tenth the frequency of the input pulses are derived from the other anode of the last unit.

Important objects of the invention are the provision of an improved counter of the feed-back type which requires no preliminary adjustment, other than resetting, for successive operational periods; the provision of an improved counter which is oi. relatively simple construction; and an improved method of indicating electrical impulses in groups of ten or the like.

The invention will be better understood from the following description considered in connection with the accompanying drawing and its scope is indicated by the appended claims.

Referring to the drawings:

Fig. 1 is a wiring diagram of one form of the improved counter.

Fig. 2 is a wiring diagram of a preferred form of the improved counter and Fig. 3 is an explanatory diagram relating to the operation of the circuit of Fig. 2.

In this figure, the four multivibrators are indicated by the reference numerals V-i, V2. V--3 and V-l. These various units have anodes II and I2, I3 and l4, l5 and I6, and I1 and II respectively. As is well known, current flows through only one anode of each pair at a time. Current is transferred from one anode of the pair to another (1) in response to the application of a negative pulse to the grid of an anode which is conducting, (2) in response to the application of a positive pulse to the grid of an anode which is not conducting or (3) in response to the application of a negative pulse to the common anode terminal 01' the unit.

Potential for operating the units is applied from a lead I! to the common anode leads of the units through resistors 20, 2|, 22 and 23 respectively. Between the common anode lead and each anode of each unit is connected impedance means The anode II of the the unit V-l is coupled through a capacitor II to the common anode terminal of the unit V -4. Output pulses at a frequency one tenth that of the applied pulses is derived from the anode I! of the unit V-4 through a lead 33.

The anode ll of the unit V-4 is "coupled through'a capacitor 29 to the anodes of a duodiode 3|. One anode ll of the duo-diode It is connected to the right hand grid of the unit V-l. The other anode 32 of this duo-diode is connected to the right hand grid of the unit V-Z. As hereinafter more fully explained, the function of the duo-diode 3| is to prevent the signal from the preceding units V-2 and V-3 from beingfed into the unit V-4 so that the units V--2 and V-3 are prevented from operating during a certain stage of the operation.

Negative bias potential is applied to the grids of the various units through a lead 34 and a reset switch 35 is opened and closed to establish a standby condition with current in the various units as indicated by the arrows.

The cycle of operation is indicated by the following chart wherein the pulse numbers are tabulated in the first column and the position of current in the various units are indicated by arrows in the following columns. For example the chart shows that the second pulse functions to transfer current to the right hand side of the unit V--l and to the left hand side of the unit V2 but does not afiect the currents of the units V3 and V-4.

Unit No.

12 1s 14 15 1o 11 i8 1 Transmitted pulse.

I Feed back takes place.

It will be observed that the operation of the counter is normal up to the application of the seventh pulse. In the absence of the duo-diode connection, the response to a count of eight would be a transfer of current from the left to the right sides of all the units. The negative potential of the anode ll, however, functions through the duodiode to prevent the right hand grids of the units V2 and V3 from becoining positive so that the urrents of these units are not transferred. us only the units V-l and V-l, have their currents transferred in response to the eighth count. The ninth count only transfers current to the left hand side of the unit Vi. The tenth count transfers current to the right hand sides of all the units and causes a negative output pulse'to be delivered at the terminal 33. Thereafter, the same cycle of operation is repeated so ion as negative pulses are applied to the input ter 24.

The coimt indicating system includes lamps I and I to 8 and resistors 36 to 52 which are connected between the lamps and various points of r the units V-l, 'v z, v a and v-4. This network applies potential to the lamps in such a way that only one lamp corresponding to the count is lit at any given time. This is accomplished by connecting the lamps in pairs through parts of the resistor network to such points of the multivibrator unitsv as provide the resultant voltages required for lighting the lamps or providing indications in the correct order.

Thus the lamps Ii and I have their common terminal 53 connected to the anode i4 through the resistor 44 and to the anode i6 through the resisof the unit V-l through the resistor 39. The

common terminal 54 of the

lamps

2 and 3 is connected through the resistor 42 to the anode l3 and through the resistor 58 to the anode IS; the common terminal 55 of the lamps 4 and 5 is connected through the resistor 46 to the anode l4 and through the resistor 49 to the anode l5;' the common terminal 56 of. the lamps 6 and I is connected through the resistor 48 to the anode l5 and through the resistor 52 to the anode i8; and the common terminal 51 of the

lamps

8 and 9 is connected through the resistor 5| to the anode I 1.

Assuming that each of the anodes I I to l8 have a potential E when they do not draw current and a potential of E0, when they do draw current, it is apparent that the common terminals 53 to 51 may be at any one of three potentials E2, E, or 12. For example, the common terminal 53 of the lamps 0 and i has a potential of E when neither of the anodes i4 and iii are taking current, of E0, when both anodes l4 and i6 are takingcurrent and of /23 when only one of the anodes l4 and iii are taking current.

With the exception of those of lamps B and l, the individual lamp terminals are connected across one or the other pair of anode resistors of the unit V--l so that the potentials of these terminals have a value of E, or V 152 depending on which anode of the Vl is conducting current. The individual terminal of lamp 6 is connected through the resistor 31 to the anode Ii and through the resistor 45 to the anode H. The individual terminal of the lamp 1 is connected through the resistor 4| to the anode l2 and through the resistor 43 to the anode 14. With these connections, the potentials of the individual leads of the lamps 6 and I change between E0, E and Ali or in the same way as the potentials of the common terminals of these lamps. This is made necessary by the fact that the common terminabof the lamps B and i may be at zero potential for the counts of 4, 5, 6 and 7 and the lamps 6 and I would also indicate a count of 4 and it they were connected to the unit'V-I in the same way as the other lamps.

Each 01' the various lamps is lit only when it is subjected to the voltage E1=EEo, i. e. difference between potential at the plates of a multivibrator when at standstill. How the voltages of the different lamps vary as the count proceeds is shown by the following tabulation:

With these connections, the individual terminals Lamp No. Pulse No..

0 1 2 a 4 s a 1 s 9 E VE E %E E' VE yE E0 E 1 E o EL 2 613 34E 0 %E 2 o 2 0 E o A E E0 Ea %E %E 54E %E 54E 34E E E 1: E %E E VE E 1 E0 yE %E E l 1 ME EL 0 VZE 2 0 %E %E 2 o %E 0 E0 E0 AE ME VJ %E %E E E E %E E 13 E %E E 36E E %E 2 36E E1. /E o /E %E o o E %E /E En E0 E E 2 }/2E %E E E E E %E E E E 1 E E 1 E E a 0 ME zE EL 2 34E 0 A 0 %E A E 0 E %E Eu Et E E ,QE %E E E E ME E /613 E. %E /6!) Eu E VB 4 EE 0 ME EL ME ME 0 o 2 gE E E E E0 E0 E0 E0 E E 34E E E E iE E En %E %E E t m: %E o VQE EL 0 %E 1/E o 16E %E E E E0 E0 Eu E) E E E yE E E E E E 1 E E I E 6 o 2 %E E 2 0 }3E 2 0 EL A iE 0 A %E E E %E VzE /E VZE En Eu E E 34E E VE E gE E VE E E E 1 E o 2 0 EE 0 EE 2 54E EL %E 0 E E %E %E 34E AE E0 E0 E E E 54E E 36 E 14E E E E 34E 8 0 16E VQE 0 ME 0 E -E E 1 E E E AE %E %E %E 34E ME 54 E0 L E0 A %E E %E E %E E yE E 1 E E 9 56E 0 0 AB 0 EE o %13 A E E1,

E E /E $E E %E LQE %E E0 E0 NOTE:

0 Ineach block c a is the potential applied to the top of lam s b is the potential applied to the bottom of connection of grou c is the net potenti r'nps or to the common s 0! two's: 0-1, 2-3, 45, 67, and 8-9: across the lamps.

Z@ @Z l b When The circuit of Fig. 2 is similar to that of Fig. 1 in most respects but differs therefrom in that (1) the feed-back is from the unit V--4 through a capacitor 60 and a resistor 6| to the unit V3 and from the unit V3 through a capacitor 62 and resistor 63 to the unit V-2 instead of from the unit Vl through the capacitor 29 and the duo-diode 30 to the units V-2 and V3, and (2) the indicating network 36 to 62 is replaced by a simpler indicating network 69 to BBQ Under these conditions, feed-back between the units Vl and V3 and between the units V3 and V2 occur at different times so that the use of an indicating network which is simpler and provides a higher voltage at the indicators 0 and l to 9 is made possiblea Another advantage oi the circuit of Fig. 2 is that the use of of the

indicators

0, 2, 4, 6 and 8 are more negative when the anode H is conducting and more positive when the anode II is not conducting. Similarly the individual terminals of the indicators I, 3, 5, I and 9 are more negative when the anode I2 is conducting and more positive when this anode is not conducting.

By opening and closing the reset switch 35. there is established a standby condition with current flowing through the anodes I2, M, iii and I8 as indicated by the arrows.

The condition of the circuit of Fig. 2 at the various stages of its operating cycle is shown by Fig. 3 wherein the input impzzlsc number is shown in the first line at the top and the voltage 75 condition of the anodes II to l8 at each of the 7 pulses is shown by the curve to the right corresponding anode numeral.

Thus with current in the various units as indicated by the arrows, the pulse leaves the anodes II, I3, I! and I1 at a more positive potential and the anodes I2, It, It and I. at a more negative potential. Under these conditions, the line it is at a more negative potential because anodes I4 and I8 are conducting the lead 65 is at a less negative potential because the anode I3 is not conducting, the lead 66 is at a less negative potential because the anode I is not conducting, the lead 61 is at aless negative potential because the anode I1 is not conducting and the lead 88 is still less negative because neither the anode ll nor the anode I1 is conducting. At the same time, the individual leads oi the indicators l, 3, '5, I and 8 are more negative because they are connected to the anode I2 which is conducting, and

oi the the individual leads of the indicators 0, 2, l, 6

and I are more positive because they are connected to the anode II which is not conducting. It therefore follows that the indicator 0 is the only one of the indicators which has the maximum voltage applied to its terminals.

The only eifect of the 1 pulse is to shift current from the anode I2 to the anode II. This extinguishes the indicator 0 and lights the indicator I which is connected to the conducting anodes I4 and I8. All the other indicators are connected to one conducting and one non-conducting anode and are not lighted.

The eflect of the 2 pulse is to shift current from the anode II to the anode I2 and from. the anode II to the anode I3 so that the lead 85 is now the only lead connected to two conducting anodes. The indicator 2 is therefore lighted.

The only cifect of the 3 pulse is to shiift current from the anode I2 to the anode II and to light the indicator 3 which together with the indicator 2 is connected to the conducting anodes I3 and I6.

The eifect of the 4 pulse is to shift current from the anode II to the anode I2, from the anode I3 to the anode I4, from the anode I6 to the anode I5 and (due to the: feed-back 62-63) from the anode I back to the anode I3 so that only the anodes I2, I3, l5 and I8 are conducting. Under these conditions, the lead 66 is the only one connected to two conducting anodes and the indicator 4 is lighted.

The only effect of the 5 pulse is to shift current from the anode I2 to the anode II thus lighting the indicator 5.

The eflect of the 6 pulse is to shift current from the anode II to the anode I2, from the anode I3 to the anode II, from the anode I5 to the anode I6, from the anode I8 to the anode IT, and (due to the feed-back Gil-6|) from the anode I6 back to the anode I5 so that only the anodes I2, II, I5 and I! are conducting. Under these conditions, the lead Bl is the only one connected to two conducting anodes and the indicator 6 is lighted.

The eilect of the 7 pulse is to shift current from. the anode I2 to the anode II thereby lighting the indicator 1.

The effect of the 8 pulse is to shift current from the anode II to the anode I2 and from the anode It to the anode I3 so that only the anodes I2, I3, I5 and Il are conducting. Under these conditions, the lead 68 is the only one connected to two conducting anodes (I3 and I1) and the indicator 8 is lighted.

The eiiect oi the 9 pulse is to shift current from Ill) the anode I! to the anode II thereby lighting the indicator 9.

The eflect oi the 10 pulse is to restore the original standby condition so that only the anodes I2, It, It and I! are conducting.

These various steps are shown diagrammatically by the following tabulation which is selfexplanatory.

Pulse 1 Transmitted pulse.

able in that it provides a relatively wide swing,

of voltage across the lamps so that they are very effectively lighted and extinguished. As previously indicated, the counter itself also has the advantage of economy of parts and simplicity of operation.

What is claimed is: I.

1. The combination of four trigger circuit units, means connecting said trigger circuit units in cascade to provide operation of each of said units except the first by an immediately preceding unit in said cascade connection, means coupled the first of said units for applying voltage pulses to the first of said units, and feed-back connections between the third and second and between the fourth and third of said units for establishing a cycle of operation such that one pulse is delivered by the fourth of said units in response to ten of said pulses.

2. The combination of four trigger circuit units, means connecting said trigger circuit units in cascade to provide operation of each of said units except the first by an immediately preceding unit in said cascade connection, means coupled to the first of said units for applying voltage pulses to the first of said units, and feedback connections between the fourth and the second and third of said units for establishing a cycle of operation such that one pulse is delivered by the fourth of said units in response to ten of said pulses.

3. The combination of a plurality of trigger circuit units, means connecting said trigger circuit units in cascade to provide operation of each of said units except the first by an immediately preceding unit in said cascade connection, means coupled to the first of said units for applying voltage pulses to the first of said units, and means including a duo-diode connected between an anode of the last of said units and certain control grids of a preceding pair of said units for rendering said pair of units unresponsive to a pulse immediately following a pulse by which current is transferred from one to another of the anodes of said last unit.

4. The combination of four trigger circuit units, means connecting said trigger circuit units in cascade to provide operation of each of said units except the first by an immediately preceding unit in said cascade connection, means coupled to the first of said units for applying voltage pulses to the first of said units, and means connected between the last and the second and third of said units for rendering said second and third units unresponsive to a pulse immediately following a pulse by which current is trans ferred in one direction between the anodes of said last unit.

5. The combination of a plurality of trigger circuit units each including a pair of electron discharge elements having anode, cathode and grid electrodes, the grids and anodes of each pair of electron discharge elements being cross-connected, means connecting said units in cascade to provide operation of each of said units except the first by an immediately preceding unit, means coupled to the first of said units for applying voltage pulses to the first of said units, and means connected between an anode of the last of said units and predetermined control grids of a preceding pair of said units for rendering said pair of units unresponsive to the pulse immediately following the pulse by which current is trans ferred to said anode.

6. A counter including first, second, third and fourth units each having input and output terminals and each including a pair of electron discharge elements having anode, cathode and grid electrodes, each of said pair of electron discharge elements having their anodes and grids cross connected so that current is conducted by either one or the other of said elements; means coupling the output terminals of the first, second and third of said units respectively to the input terminals of said second, third and fourth units; means coupled to the first of said units for applying input pulses only to the first of said units; a feedback connection between the fourth and third of said units; and a feedback connection between the third and second of said units, said feedback connections being such that one pulse is delivered at the output terminals of said fourth unit in response to ten of said input pulses.

7. A counter including first, second, third and fourth units each having input and output terminals and each including a pair of electron dissaid units for indicating on a decimal scale of ten the number of said input pulses.

8. The combination of four trigger units each including a pair of electron discharge elements having anode, cathode and grid electrodes, the grids and anodes of each pair of electron discharge elements being cross-connected, means connecting said units in cascade to provide operation of said units except a first of said units by an immediately preceding unit, means coupled to a first one of said units for applying voltage pulses to said first one of said units, and means to couple certain ones of the last three of said units to apply to the second and third of said cascaded units reset pulses during the application of ten voltage pulses to the first one of said units to provide a cycle of operation which is completed in response to ten of said voltage pulses being applied to said first one of said units.

9. The combination of four trigger units each including a pair of electron discharge elements, each of said electron discharge elements having anode, cathode and grid electrodes, the grids and anodes of each pair of electron discharge elements being cross-connected, means connecting said units in cascade to provide operation of each of said units except a first of said units by an immediately preceding unit, means coupled to said first one of said units for applying voltage pulses to said first one of said units, and feedback means connected between subsequent ones of said last three units in said cascade and preceding ones of said last three units in said cascade to apply reset pulses during the application of ten voltage pulses to said first one of said units to provide a cycle of operation wherein one output pulse is delivered by the last one of said units in response to ten voltage pulses being applied to i said first one of said units.

charge elements having anode, cathode and grid electrodes, each of said pair of electron discharge elements having their anodes and grids cross connected so that current is conducted by either one or the other of said elements; means coupling the output terminals of the first, second and third of said units respectively to the input terminals of said second, third and fourth units; means coupled to the first of said units for applying input pulses only to the first of said units; a feedback connection between the fourth and third of said units; a feedback connection between the third and second of said units, said feedback connections being such that one pulse is delivered at the output terminals of said fourth unit in response to ten of said input pulses; and means interconnecting the output terminals of 10. A counter including first, second, third and fourth units each having input and outputterminals and each including a pair of electron discharge elements having anode, cathode and grid electrodes, each of said pair of electron discharge elements having their anodes and grids cros'sconnected so that current is conducted byeither one or the other of said elements and operation of one of said units to transfer current conduction from. one to the other of its elements is effectuatedby application of a pulse to said unit input terminal, means coupling the output terminals of the first, second and third of said units respectively to the input terminals of said second, thirdand fourth units; means coupled to the first of said units for applying input pulses only to the first of said units; and a pair of feedback circuits each connected between a different pair of the last three of said units, each of said feedback circuits in each pair of said units connecting an anode of one of said pair of units to a grid of the other of said pair of units to operate said other of said pair of units when said one of said pair of units is operated for the first time from the preceding unit connected to its input terminals, said feedback circuit connections being such that only one pulse is delivered at the output terminals of said fourth unit in response to ten of said input pulses.

IGOR E. GROSDOFF.

(References on following page) REFERENCES CITED The following references are of record in the me of this patent:

UNITED STATES PA'I'ENTIB Number Name Date Hollywood Dec. 29, 1942 Pearson et a1. Feb. 29, 1944 Miller Aug. 14, 1945 Miller Sept. 10, 1946 12 Number Name Date 2,410,158 Flory Oct. 29, 1940 2,422,698 Miller June 24, 194'! OTHERCE Electronics, June 1944, pp. 110 to 113, 358 and m 360: "A Four-Tube Counter Decade. by John T. Potter.